Explosionproof switch panel



May 16, 1939. R. H. dLLEY EXPLOSIONPROOF SWITCH PANEL Filed April 8, 1937 4 Sheets-Sheet l WW BY lm z May 16, 1939. R. H. OLLEY 2,153,477

EXPLOSIONPROOF SWITCH PANEL Filed April 8, 1937 4 Sheets-Sheet 24 IN VENTOR.

ATTORNEYS May 16, 1939'. OLLEY 2,158,477

' EXPLOSIONPROOF SWITCH PANEL Filed April 8, 1937 4 Shets-Sheet 4 y]? Z! INVENTOR. BY

ATTORNEYS,

Patented May 16, 1 939 UNITED STATES PATENT OFFICE EXPLOSIONPROOF SWITCH PANEL Application April. 8, 1937-, Serial No. 135,823

3 Claims.

This invention relates to an enclosed explosloncuring the ends of said conduits to said switch proof switch panel, and has for an object a construction and arrangement which is particularly economical to manufacture and assemble.

A further object of the invention is a switch panel ofthe type referred to which, because of its novel construction and arrangement of parts, is particularly easy to install, including the connection of the main and branch electrical circuits.

A further object of the invention includes a construction by which the switch panel may be readily assembled with any number of switches to accommodate any particular situation, and the invention includes the provision of means where-- by the individual switch housings are respectively connected to the main wiring compartment of the panel by individual conduits, and means isprovided for detachably securing the free ends of these conduits to the individual switch housings and separating the interior of the switch housings from the conduits by a flame tight partition not involving the use of molten sealing compounds.

The invention consists in the novel features andin the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

Figure l is a front elevational view, partly in section, of the switch panel.

Figure 2 is a side elevational view of the switchpanel with parts shown in section.

Figure 3 is a sectional view taken on lines 3-3, Figure 1.

Figure 4 is a sectional view through one of the switch housings taken on lines 44, Figure 1.

Figure 5 is a sectional view of the switch housing taken on lines 5--5, Figure 4.

Figure 6 is a sectional view taken on lines 6-6, Figure 1, in which the switch housings are shown in end elevation.

The invention consists generally of a body section comprising a main wiring compartment and a supporting member secured to and. extending transversely of the ends of the body section and extending outwardly from one side of the body section, a plurality of enclosed switch housings detachably secured to each of said supporting members and extending transversely thereof, a plurality of conduits extending from said body section and terminating respectively adjacent said switch housings, means for detachablysehousings, each of said switch housings and said body sections being provided with an opening in one wall thereof, and a flame tight closure for each of said openings.

The invention, in its preferred embodiment, further comprehends a tubular wiring compartment extending from the side wallof said body section and arranged intermediate said supporting members and switch housings mounted thereon.

The switch panel is usually mounted in vertical position, as shown in Figure 1, upon the wall or a post, or other suitable support. The body section lii'is formed of cast metal, and is here shown as elliptical in general cross sectional form with the end walls II and a side wall 12 provided with a plurality of hubs I 3 to receive the branch conduits M. The hubs l3 may be provided with the conventional threaded aperture to receive the threaded end of the conduit i4, and when any of the hubs I3 are not in use this aperture is closed by means of a screw plug !5-. The outer or topwall of the body section it! is provided with a plurality ofcomparatively large workopenings l6, these openings being threaded internally to receive closures I! in the nature of a screw plug. The rear or top wall I2 is provided with an enlarged threaded hub 18 to receive the main conduit run l9. That is, the main or feed' wires carried in the conduit iii are brought into the body section I!) and connected to suitable terminal blocks and the individual switches of the panel are in turn wired to the respective terminal blocks, and the branch circuits controlled by the switches are carried out through the branch conduits M.

The bottom wall of the body section It! is formed with a comparatively large, centrally arranged aperture 20 threaded internally. The aperture 20 is arranged in alinement with the aperture in the hub l8, and may be of the same dimension as the aperture in hub l8 to permit the panel to be inserted in the run of the main conduit line. When the switch panel is connected to the end of the main conduit run, the aperture 20 is closed with a screw plug. Preferably, the aperture 20 is enlarged to receive one end of a tubular'housing or section 22, the opposite end of which is provided with an internally threaded hub 23'to receive the conduit. One side of the central portion of the tubular section 22 is cut away, asat 24} to permit access to the in"- terior of the section 22 and to the terminal blocks 25 mounted therein. That is, the central cross 55 section of the section 22 is substantially troughshaped, and the tubular section is enclosed by an elongated sleeve 36 threaded internally at each end with the threaded portions being complemental to external threads provided on the ends of the sections 22, whereby the sleeve 2% may be threaded axially of the section 22 and act as a closure for the section, as indicated in Figure 3.

The sleeve 2'6 is held from displacement by a snap ring 2i? located in a peripheral groove at the outer end of the section 22. This arrangement permits for a through feed on the main conduit line, and permits one or more terminal blocks 25 to be located outside of the main wiring compartment in body it} to effect greater ease of installation and wiring. The tubular section 22 is formed with inwardly extending bosses 28 arranged adjacent the bottom of the section, and on which is detachably mounted a terminal block supporting plate 29 by means of screws 30.

The terminal blocks 25 are provided with large main terminals 32 to which are connected the main feed conductors 33 carried in main conduit l9, and the terminal blocks 25 are provided with a plurality of smaller branch terminals 3 3 to which conductors are connected, and which run to the individual switches or circuit breakers hereinafter referred to.

As here shown, one of the terminal blocks connected to the main feeds 33 is located in the cen tral portion of the wiring compartment. This terminal block is designated as 55 and preferably the neutral wire of the system is connected to the terminals of this block, the outside wires of the system being connected to the terminal blocks 25 located in the tubular housing 22.

As shown in Figure 1, two terminal blocks 25 are installed in the tubular section 22 to accommodate a three wire system, and in Figure 3, three terminal blocks 25 are installed in the tubular section to accommodate a four wire system. The addition of the tubular section 22 is preferred, inasmuch as it does not add to the over-all dimension of the panel and affords a conveniently accessible compartment for the main terminal blocks resulting in less congestion in the main Wiring compartment of the body section it, particularly when the feed conductors are large, rigid cables and accordingly, permitting the panel to be wired up with greater ease and a minimum consumption of time.

The switches or circuit breakers are mounted in flame tight explosionproof housings Aid which are detachably secured to supporting members ii which are secured to the body Ell, as by cap screws l2, and extending transversely of the ends of the body. The supporting members are here shown in the nature of a channel iron 53, to which is secured an angle plate 5 1-. The bottoms of the switch housings 56 are formed with a pair of spaced apart downwardly extending bosses 25 which are provided with threaded apertures to receive the screws 16 which extend through apertures on the outer end of the angle plate l i. The switch housings til are accordingly arranged side by side and extend transversely of the supporting members ii, the outer ends of the housings being formed with a large threaded aperture to receive the threaded closures ii. The purpose of the end aperture is to permit convenient installation of the switch or circuit breaker iii, and to eifect the proper electrical connections thereto. 7

Attention is particularly called to the novel construction employed in mounting the switches 58 in the housings it]. The inner surface of the inner end wall of the housing MI is provided with a pair of spaced apart, inwardly extending bosses 49. The bosses 3 9 are bifurcated as at The bottom wall of the housing All, adjacent the open end thereof, is provided with a radially inwardly extending boss 52 provided with a threaded aperture. The switch or breaker 18 is mounted on a fiat sheet iron plate 53 formed with a downwardly extending tongue 54 which is so arranged as to come in alinement with the outer boss 52 of the housing when the inner end of the plate 53 is located in the bifurcations 5B of bosses 49. A screw 55 extends through the tongue and is threaded into the boss 52, this construction acting as an outer support for the plate 53 and switch 48, and also holding the inner end of the plate securely in the bifurcated bosses 49. It is only necessary to manipulate the single screw 55 to remove or install the switch or breaker 1-8 in the housing 4!].

The housing all may be provided with a suitable switch actuating manual. As here shown, the top wall of the housing is provided with. a bushing 6i] threaded into the top wall of the housing, and being provided with internal threads to receive the threaded stem ill, to the inner end of which is secured suitable means connecting the stem iii with the handle or actuating member 62 of the switch or breaker, and the outer end of the stem 6! provided with a suitable mandrel 63. If it is desired to lock the switches in their on or off position, the top wall of the housing may be formed with an outwardly extending boss 6 provided with an aperture 65 to receive a padlock, or the like, to prevent oscillation of the mandrel 63.

Inasmuch as the switch panel is of the explosionproof type, it is necessary that all the wires and conductors of the system be enclosed in a metallic closure, and to comply with this prerequisite I employ a separate conduit extending from the main body section Ill to each of the individual switch housings 4B. The purpose of these conduits is to enclose the wires or conductors leading to and from the circuit breakers arranged in the housings. While switch panels of this type heretofore used have functioned with perfect satisfaction, there have been two outnecting the switches or breakers to the main and branch circuits and maintaining the switch and wire compartments in flame tight relationship.

From the description thus far, it will be apparent that the wiring compartment consists of an individual casting or body section it, and the switches or breakers are mounted in comparatively small individual explosionproof switch housings which are of uniform construction and which, because of their construction and size, are comparatively easy to construct and machine. The tubular housing 22 and sleeve 25, if used, are also separate units which can be manufactured at a comparatively small cost. It will be appreciated by those familiar with the art that switch panels are constructed to meet the requirements of individual situations, and employ two or more switches or breakers. Usually all panel boards are constructed in multiple arrangement. That is, there are two, four, six, eight etc., switches employed.

An object of my invention is the structural arrangements and combinations by which any number of switch housings and switches, within practical limits, may be employed. That is, the panel may be constructed with two, four, six or eight switch housings.

The bottom wall of each switch housing is formed with an outwardly extending boss 10. This boss H! is provided with complemental threads externally and internally, and the lower wall of the body section I0, when the panel is arranged in vertical position, is provided with a series of threaded apertures H arranged adjacent the rear or back wall of the body section, see Figure 6'. The threaded apertures H are arranged on each side of the aperture 20. Conduits 12, 13, 14 and 15 are screwed into the apertures H and extend outwardly from the wall of the body section l in substantially parallel relationship to the supporting members 4|. The conduit 12 extends to the outer or lowermost switch housing, the conduit 13 to the adjacent switch housing, the conduit 15 to the switch housing mounted adjacent the body section III, and the conduit I to the switch housing arranged second from the body section II]. That is, there is a conduit extending from the body section II) for each of the switch housings 40. In order to provide ease of assembly, the housings 40 are detachably secured to the outer ends of the conduits 12 to 15.

As here shown, an elbow fitting 15 is threaded on the exterior of the boss of the switch housing, and the end of the conduit is provided with a union fitting comprising a sleeve ll and a nut 18. The end of the elbow 16 is machined to a flat surface to receive the complemental end face of the sleeve 11, and the periphery of the elbow is threaded to receive the nut 18 which coacts with the sleeve H to draw the same tightly against the end of the elbow. This construction assures a flame tight joint between the conduits and the elbows 16. It is necessary to seal the interior of the switch housings from the interior of the body section II). Heretofore, it has been conventional practice to pour molten compound in some portion of the fitting about the wires. However, due to the fact that the recess in which the molten compound is poured is generally inaccessible, it is difficult to get the compound in the recess, and particularly difiicult to effect a proper seal.

As here shown, a plug 80, formed of high heat resisting insulating material, is threaded into the bore 10 of the switch housing, and the plug 80 is provided with a plurality of threaded apertures into which metallic sleeves 8| are threaded. The metallic sleeves 81 are drilled from each end, and the metallic portion 82 of the conductors S3 are secured in the ends of the sleeves 8| by means of solder, or the like.

device is assembled by securing the wires 82 into each end of the sleeves 8|, passing the wires extending from one end of the plug through the threaded apertures thereof, and threading the sleeves Bl into said apertures. The wires, extending from one end of the plug, are of such length as to extend from the plug to the terminals of the switch in the housing. The wires, extending from the opposite end of the plug, are of such length as to extend from the plug through the conduits and into the main body section III for connection to the terminal plugs mounted therein. It will be observed that there is no difliculty in threading the respective sleeves 8!, with the wires attached thereto, into the plug 80, and

likewise there is no difficulty in threading the plug 80 into the boss 10 inasmuch as the extending wires from each end of the plug are permitted to freely rotate within and without the housing respectively. The plug 80 is only initially partially threaded into the boss 10 and is formed at its outer end with a pair of opposed projections 84, and the bore of the elbow member 16 is provided with opposed recesses complemental to the projections 84.

The elbow member 16 is sleeved over the extending wires from the plug and is threaded onto the boss 10 with the projections 84 engaging the recesses in the elbow member, whereby the elbow member is threaded on the boss 10 and the plug member is simultaneously threaded in the boss. The operations thus far described are completed prior to the time the switch housing 49 is secured to the support 4|, or angle iron 44 thereof.

The respective conduits 12, 13, I4 and are now threaded into the main body section, and the sleeves H with nuts 18 are secured to the outer ends of the conduits. The conduits l2, I3, 14 and 15 are cut to such lengths, and formed in such manner that the sleeves 11 are arranged in alinement with the outer ends of the respective elbow members 16. After the wires 83 have been secured in the switch housing 40 in flame tight relationship thereto in the manner above described, the wires extending outwardly from the switch housing are passed through the respective conduits 12, l3, l4 and 15, the switch housing secured to the support member 4!, and the nuts 18 tightened. The wires extending from the switch terminals into the main body section 10 are thus totally enclosed, and the switch housings are sealed ofi from the connecting conduits in a flame tight manner so that an explosion occurring in the switch housing will not carry back into the main body section, and at the same time the individual switch housings are conveniently attached to the panel, or removed therefrom. It will be understood that if the panel is initially equipped with two switch housings, the apertures H, not used, will be closed by a suitable plug. If desired, additional switch housings may be conveniently added subsequently as above described.

It is believed the advantagesresulting from the structures employed in my switch panel will be obvious to those skilled in the art without further detail reference to the same.

What I claim is:

1. An enclosed switch housing provided with a threaded aperture in one wall thereof, a conduit enclosing a plurality of conductors, a plug threaded into said aperture and being formed with a plurality of threaded apertures extending there through, each of said conductors being provided with an externally threaded sleeve, said sleeves being threaded into the respective threaded aper tures of said plug, and means for detachably connecting one end of said conduit to the switch housing in register with the aperture formed therein.

2. An enclosed switch housing formed with an externally threaded hub on one wall thereof, and said hub being provided with an internally threaded aperture, a conduit enclosing a plurality of conductors, a plug member threaded into the aperture of said hub, each of said conductors extending through said plug member in flame tight relationship therewith, a coupling member secured to one end of said conduit and threading on said hub, and being cooperable extending through said plug in flame tight reI'ationship thereto, a coupling member carried by one end of said conduit and threading on said hub and being cooperable with said plug member to prevent relative rotation between said plug member and said coupling.

RAYMOND H. OLLEY. 

